Adds devcontainer, and poetry for dependency management only

[hollanbm]

• Adds devcontainer for consistent/repeatable dev environment

  • configures vscode with sane defaults for project
  • zsh/oh-my-zsh default shell
  • enables popular shell extensions
  • docker-in-docker support

• Adds poetry for dependency management only

  • flake8, pylint, dev dependencies (and vscode extensions)
  • pytest test dependency (and vscode extension)
  • Refactored PlexAniSync Dockerfile for readability
  • Container no longer runs as root
  • app user is created
  • app user creates/activates venv with poetry
  • Eliminated two stage build, in favor of poetry venv

I built and tested the refactored container image

 ✔ Container plexanisync  Recreated                                                                                                                          0.1s 
Attaching to plexanisync
plexanisync  | Updating settings.ini
plexanisync  | 2024-05-12 05:46:29 PlexAniSync - version: 1.4.0
plexanisync  | 2024-05-12 05:46:29 [MAPPING] Custom map file not found: custom_mappings.yaml
plexanisync  | 2024-05-12 05:46:29 [ANILIST] Retrieving AniList list for user: <user>
plexanisync  | 2024-05-12 05:46:30 [ANILIST] Found 201 anime series on list
plexanisync  | 2024-05-12 05:46:30 [PLEX] Retrieving anime series from section: Anime
plexanisync  | 2024-05-12 05:46:31 [PLEX] Found 220 anime series in section: Anime
plexanisync  | 2024-05-12 05:46:31 [PLEX] Retrieving anime series from section: Anime Movies
plexanisync  | 2024-05-12 05:46:31 [PLEX] Found 95 anime series in section: Anime Movies

[hollanbm]

@reconman I suspect there will be a little back and forth on this. But I saw an opportunity to improve the app dev experience and dependency management with poetry

I'm not exactly sure what the Tautulli Dockerfile is doing, if you could give some backstory on that, I'll do my best to refactor it as well to leverage poetry.

I'm also not sure what the additional repo config in pip.conf does. I tried to see if poetry supported pip.conf and it doesn't. So I went ahead and just deleted the file.